The Gatehouse website record of a licence to crenellate for Chillingham Castle granted on 1344 Jan 27

Licence for Thomas de Heton to crenellate his dwelling-place of Chevelyngham and make a castle or fortalice thereof. By p.s. (CPR)

Thomas de Heton ... mansum suum de ac castrum sive fortalicium inde facere ... Chevelyngham. (Turner and Parker)

mansum suum de Chevelyngham ... at castrum seu fortalicium inde facere (Bates)

Edwardus Dei gratia Rex Angliae et Franciae et Dominus Hiberniae omnibus ballivis et fidelibus suis ad quos presentes literae pervenerint salutem. Sciatis quod de gratia nostra specialiter concessimus et licenciam dedimus pro nobis et heredibus nostris dilecto et fideli nostro thomas de Heton quod ipse mansum suum de Chevelyngham muro de petra et calce firmare et kernellare et castrum seu fortalicium inde facere et mansum illud sic firmatum kernellatum et castrum seu fortalicium inde factum tenere possit sibi et here-dibus suis sine occasione vel impedimento nostri vel haeredum nostrorum vicecomitum aut aliorum ballivorum seu ministrorum nostrorum quorumcumque. In curia rei testimonium has literas nostras fieri fecimus patentes et teste me ipso apud Westm' vicesimo septimo die Januarii anno regni nostri Angliae decimo octavo regni vero nostri Fraunciae quinto. (Transcription by Philip Davis)
Edward by the grace of God, King of England and France and Lord of Ireland, to all his bailiffs and liege subjects, to whom these present letters shall come, greeting. Know, that by our special grace, for ourself and our heirs, we have granted and given freedom to our beloved and faithful Thomas de Heaton, for his manor house of Chillingham, to strengthen it with a wall of stone and mortar and battlement it and make it a castle or fortalice and that house, so battlemented and made into a castle or fortalice to be held, regardless, by him and his heirs without let or hindrance from us or our heirs, sheriffs, or other of our bailiffs or ministers whatsoever. In the Court, concerning the matter of this testimony, we have made these our letters open. Testified by the witness of myself at Westminster on the twenty-seventh day of January in the eighteenth year of our reign of England, the fifth of our reign of France. (Translation by Philip Davis)

Comments

An uncommon licence to build a castle, although in the context of 14th Northumbrian high status houses the fashion was for thick walled houses and tower houses a fashion clearly derived from the strong military tradition of the border and the occasional raids from Scotland and the threat of war, sometimes realised. It is important neither to overstate nor understate the military aspects of houses of this type in this area.
Regardless of being granted a licence or not Thomas Heton would have built a house of this type because it was both the local fashion and would show his status but also to offer some actual protection to his family and his goods.

Original source is;

Lyte, H.C. Maxwell (ed), 1902, Calendar of Patent Rolls (1343-45) p. 191 online copy
The original survives and is held at the castle where it is on display..

(In fact, the original source given is usually a transcription/translation of what are precious medieval documents not readily availably. It should be noted that these transcription/translations often date to the nineteenth or early twentieth centuries and that unwitting bias of transcribers may affect the translation. Care should also be taken to avoid giving modern meaning to the medieval use of certain stock words and terms. Licentia is best translated as 'freedom to' not 'permission'.)

Significant later sources are;

Emery, Anthony, 1996, Greater Medieval Houses Vol. 1 (Cambridge) p. 159
King, D.J.C., 1983, Castellarium Anglicanum (London: Kraus) Vol. 2 p. 366n84
Bates, C.J., 1891, Border Holds of Northumberland (London and Newcastle: Andrew Reid) p. 9
Longstaff, W.H.D., 1859, Gentleman's Magazine Vol. 9 part 2 p. 504 online copy
Turner, T.H. and Parker, J.H., 1859, Some account of Domestic Architecture in England (Oxford) Vol. 3 part 2 p. 413 online copy

Thomas Heaton (1288-1357)